A pretty poor attitude to perfectly good freedoms

Many years ago, a hacker named Phil Zimmermann wrote a program which enabled one to encrypt email messages using a technique called public-key cryptography. He called it Pretty Good Privacy (PGP) and posted it on the net so that Joe Public could have the same kind of encryption facilities that spooks take for granted.

Not surprisingly, the spooks went ape-shit. Using a preposterous legal argument, the US government defined PGP as 'ammunition', thereby making it subject to laws prohibiting the export of weaponry without the express permission of Uncle Sam. They prosecuted Zimmermann on charges that could have landed him in jail for years. PGP was still available on the net, but anyone downloading it from outside the US was committing a criminal offence, for which they could in theory have been extradited to the US.

While all this was going on, I was browsing in a (British) university library and came upon a massive bound volume entitled Pretty Good Privacy. It consisted of hundreds of pages of computer printout and was, in fact, the source code of the PGP program. If I had the time (or access to a good scanner) I could have used the book to create a working copy of the program Zimmermann was banned from exporting from the US.

It was my first glimpse of a distinction which may become critical for basic cyberspace freedoms. While the US government could control the publication of PGP in computable form, it couldn't exert that control on the written version of the program: the written version would enjoy the protection of the First Amendment and meddling would therefore have been unconstitutional.

This legal nicety has suddenly become very important in relation to DeCSS, the program for decrypting DVD disks so they can be played on computers using the Linux operating system. In a Manhattan court, eight Hollywood studios are suing the publisher of 2600, a hacker magazine, for posting the DeCSS code on his website. This, they say, contravenes the Digital Millennium Copyright Act, which makes it illegal to devise ways of circumventing copy-protection schemes such as the CSS system, which protects DVD movies.

The case was going swimmingly for the movie moguls until Professor David Touretzky, a computer scientist at Carnegie-Mellon University, took the stand as an expert witness. He produced a series of exhibits that included lines of software source code in the C computer language, an English-language description of the code, long strings of ones and zeros (known as object code) and a picture of a T-shirt with the DeCSS object code printed on it. The point of this exercise was to make a devastatingly simple point: if the judge saw fit to ban any one depiction of the DVD-unscrambling software, he would have to ban them all, because they all communicate the same thing.

'I see this as having a chilling effect on my ability as a computer scientist to express myself,' Touretzky said. 'If the court upholds this injunction, what would happen is that certain uses of computer language - my preferred means of expression - would be illegal.'

At this point, according to the New York Times reporter present, there was a sharp intake of breath among m'learned friends. The judge, who had hitherto seemed inclined to the view that computer code was no more expressive than an automobile ignition key, suddenly declared that he would have to reconsider his constitutional analysis.

'It would be hard to make a case that computer code of any kind has no expressive content,' he said. 'Which then gets you to the question of how then do you deal with it under the First Amendment?' Precisely. Stay tuned.